Air control for locomotives



1947- v. MANSFIELD ,415,256

. AIR comer. 30a nocolouvss I Filed July 30, 1945 5 Sheets-Sheet 1 6 24" 1 04/ 0 MmSf/w j a, MAW

Feb. 4, 1947. v. MANSFIELD 2, 15,

, AIR coll'mol. roa LOCOIIOTIVES Filed July 30. 1945 5 Sheets-Shoat 2 uuuu F7940 "j I 9mm Vaughn Mans fie/0 r Feb; 1947- v. MANSFIELD A'IR CONTROL FOR LOCOMOTIVES Filad July 30, 1945 5 Shuts-Sheet 3 grwm w h v 1 Q2. k k hm a1.

Feb. 4,. 1947. v, snEL 2,415,256

AIR CONTROL FOR LOCOIOTIVBS Filed Juli so, 1945 5 shuts-Sb 4 Feb. 4, 1947. v. MANSFIELD AIR CONTROL FOR LOCOMOAPIVES Filed July 30, 1645' 5 Sheets-Sheet 5 INVENTOR.

BY p I Patented Feb. 4, 1947 UNITED STATES PATENT OFFICE 2,415,256 AIR CONTROL FOR LocoMo TIv'Es Vaughn Mansfield, Memphis, Tenn. Application July 30, 1945, Serial No. 607,804

' 13 Claims. (01.110-76) r This invention relates to locomotives and, more particularly, to apparatus for providing and maintaining complete and uniform distribution of air in the fire box of a coal-burning locomotive. a

In coal-burning locomotives of the type now in use, it has been found that the combustion efficiency averages less than 55 per cent in road service at high burning rates and that the efliciencies of the few best designs range only from 60 per cent to 65 per cent, with the greatest losses resulting from unburned cinders and dry gases. Intensive survey 'has revealed that com-- bustion inefiiciency is directly attributable to improper air distribution and feed through the grate area, and while the many locomotives tested had substantiall the same per cent of air 2 tion previously obtained when a locomotive was standing, .but when the locomotive moved forwardly, a rearward component was added to the air flow so that at normal or high speeds, the incoming air was directed to the rear of the fire box in excessive amounts and at undesirably high velocities, and relatively little air entered the front portion of the fire box. As a result, firemen opening through the grates, there was a wide difference in the per cent of air fiow into the ash pans. Furthermore, repair for such items as arch brick maintenance, cinder cutting,- and tube slagging were proportional to the degree of restriction of air flow to the ash pans; These items represent a large per cent of engine maintenance and repair. It is therefore the object of this invention to provide for introduction of suflicient air uniformly distributed into ash pans of locomotives. V

A further phenomenon discovered was the gross discrepancy in air flow in different portions of the fire box in a series of measurements'taken with an anemometernot only from front to rear,

' but also from side to side. Another aspect of this invention is the equal distribution of air fed into the ash pan with a resultant equalization of draft through and above the fire.

In accordance with the broader objects of the invention, it is now proposed to provide a series traditionally built up a prodigious and ineificient bank of coal in the rear' of the fire box, and even blind rear grate sections have been tried to prevent the rear part of the fire bed from being blown out of the grates. Whereas these former practices treated the symptoms of the disorder and but served to cut down the efiective grate area with resultant low combustion efiiciencies, it is now proposed to rectifythe cause by installing baflies to prevent the rearward flow of air as it enters the ash pan openings. Yet another object is to provide a drop door on the outer side wall of the cleaning.

Still another object is to provide a series of baflles extending transversely of the direction of travel of the locomotive, the bafiles being spaced from one another in accordance with the volume of bafiies along an ash pan vtrough, the baffles being spaced from one another in accordance with the relative furnace volume above the grate section lying inwardly therefrom. Thus it is intended to feed difi'erent grate sections in accordance with their diiferent needs, to prevent irregular draft from pulling too much air through small areas, and also to prevent the pulling of air to one part of the fire box from the portion of the ash pan trough which should supply air to another part of the fire box, and to prevent the formation of eddy currents in the air passing into the ash pan.

Another feature of the invention resides in the maintenance of the direction of air entering the ash pan at substantially right-angles to the foreand-aft dimension of the fire box. This condiof the primary combustion region of the fire box,

lying immediately inward of the bafiies so that the spaces between the baiiles vary from front to rear to maintain air fiow proportional to the furnace volume above-each grate section. Furthermore, it isintended that the effective height of the ballles increase from front to rear so that each bafiie will catch and deflect the proper amount of air for the space between it and the preceding baffle.

Another object of the invention is to provide, in combination with a series of bafiles spaced along the ash pan trough of a locomotive and extending transversely of the fore-and-aft dimension of the trough so that incoming air will be deflected laterally'inward into the ash pen, a relatively narrow longitudinal baflie extending immediatelybelow the side edge portions of the grates, with thedeflecting surface of the longitudinal baffle spaced from the inner lower edge of the mud ring and disposed at an angle to the horizontal so as to deflect a portion of the laterally moving, incoming air upwardly to the sides of thegrates. These and other objects will be apparent in the following specification and drawings, in

which:

Fig. 1 is a diagrammatic side eleva'tionwith part of the left-hand side of the locomotive bro-- ash pan trough to facilitate ken away illustrating typical air. distribution from front to rear in a prior art locomotive fire box when the locomotive is in motion;

Fig.1a is an enlarged, detailed view of the portion of Fig. 1 showing the fire box: V v Fig. 2 is a cross-sectional illustration of the average distribution from side to side in a locomotive fire box wherein the air distribution is as shown in Fig. 1;

Fig. 3 is a diagrammatic plan view of the predominant air currents occurring in a prior art locomotive. ash pan with the arch removed; Figs. 4, 4a, '5, and 6 are diagrammatic counter-. parts, respectively, of the illustrations of Figs. 1, 1a, 2, and 3, but illustrating air distribution inthe fire-box of a locomotive embodying the invention:

front portions of the also setting up eddycurrents in thetroughs and inlet openings, particularlyat the front. Under .Fig. '7 is a graphic illustration of air pressure 1 patterns of a fire box not utilizing the invention and of a fire box similar in all respects but utiiizing the invention;

Fig. 8 is an isometric view of a locomotive ash pan showing the grates, the ash-pan. troughs, and the bailies installed; v

Fig. 9 is a crosssection bf the structure illus trated in Fig. 8 but with the grates removed;

Fig. 10 is a fragmentary section showing the baffles and a trough in detail;

Fig. 11 is a view similar to Fig. 10 but showing 'a modification of the longitudinal battles; and

Fig. 12 is a fragmentary isometric view similar to theleft-handiportion of Fig. 8 but showing baflles increasing in height from front to rear.

Referring now the drawings, inwhich like elements are denoted by similar reference numerals. Figs. 1 to 3 inclusive illustrate a prior art locomotive 2' of th Mikado type having the usual fiues 3, firebox 4, crown sheet 5, grate 6, grate rods 1, arch 8. arch tubes 9, ash pan I0, and ash i averaged from side to side, are indicated by the length of the arrows. It will be apparent that the pressure of the air flowing through the grates. and coal bed is low in the regiongbelow arch 8, and extremely high in the regions behind the arch, resulting in high burning .rates in the rear portion only of the fire box. t

Fig. 2 illustrates the sideto-side distribution at the lower side edges of the fire some conditions, gases fiow downwardly through front portions of the coal bed. It was therefore standard practice for firemen to keep a large bank of coal overthe rear-grates witha 'thin bed at the front.

Figs. 4 to 6, inclusive, illustrate the theory of the invention. In,an improved engine 20 having the same basic elements as detailed above. series of baflles 22 are spaced in troughs 24 so that air entering openings I4 is distributed evenly as illustrated. For illustrating the invention, the

combustion chamber enclosed -by firebox 4 is f considered as comprising two regions, the first being that in which primary combustion of the .coal gases occurs and comprising the space below and behind arch 8, designated 28;. the second being. that in which secondary combustion occurs and being above and in front of arch 8, designated 30. The volume of region 28 increases from front to rear, and it should be noted that the spaces .between baiiies 22 also increase from front to rear so that the bailles 22 are spaced from one another substantially in accordance with the vol-- 'ume 'of the primary combustion region 28 immediately inward thereof. Y V

Fig. 7 illustrates-moreprecisely the achievements of the invention, the base lin'eA denoting the front-to-rear dimension of a locomotive,

while dashline 32 representsanemometer readings, averaged'i'rom side to side in an unimproved fire box, and taken while the locomotive was standing. At-twelve miles per hour, the average reading at the peak rose considerably, while the of the air in the fire box of Figs." 1 and la, the

vertical arrows indicating relative velocities. Here it will be seen that strong drafts. occur at and near the center of the fire box, and that relatively little air flows through the grates and coal near the sides. The reason for these phenomena may be found in Fig. 3 wherein, as shown by the arrows, air sweeps inwardly through the troughs and inlet openings to the rear of the ash pan, and then .up through the rear center portions of. the grates. It has been found in many instances that instead of getting more air for combustion as the speed of a locomotive increases, at which time more 'air and more combustion is needed, lass total air is obtained. This is because air entering the ash pan troughs blasts backdips were more pronounced. Full line 34 shows the average readings taken under similar conditions but with baflles installed. Vertical line B represents the side-to-side dimension of a fire box, dotted line 36 representing anemometer readings averaged between front to rear in the unimproved fire box, while full line 38 represents similar readings in the improved fire box.

The structural features of theinvention are illustrated in Figs. 8- to 11, in which all elements such as arch, fire box,,et cetera not necessary'for illustrating the invention have been eliminated,

it being understood that the physical embodiment of thejinvention is applied to a standard locomotive. In these figures, it will be seen that a series of baflles 22 is mounted in each ash pan trough 24', the baiiles having their fiat surfaces parallel to one another and extending transversely of the fore-and-aft dimensions of the troughs. For convenience in cleaning, and. as

' best shown in Fig. 10, each trough is preferably divided into a fixed, strip lll arid a hinged section 42, the hinged section being supported by 'hinges 60 44 connected to the-upper lip 46 of each ashpan Ill-and releasably held in normal position by latches which compriseL-shaped strips 49 extending outwardly from fixed strip 40 through openings in hinged section 42 so that the hinged section may be swung open for cleaning out. the

troughs and pan. When closed, hinged section 42 is retained by pivoted keepers 5! which engage behind the upstanding portions of strips 49. .Any of the well-known types of latches, hooks, or the like may be used for this purpose. End walls 50'. rigidly aflixed to the ash pan close the endsof.

the troughs, and bailles 22 are welded at 52"to mud ring I 'and at ii to fixed strip portion 40 -of trough 24.

inlets to in; asiipinziand I While the upper edges of baiiies. wardly and rearwardly, thereby by-passing the 5 22 are shown flush with the upper edge. of trough upward inclination from front torear of the this figure, all elements are similar to those de- 24. they may lie above or below the upper edge of the trough, .or maybe made to extend suc- I cessively higher, progressing from front to rear,.

to accentuate the overlapping effect obtained by the upward and rearward inclination of the trough. This latter arrangement is illustrated in Fig. 12, in which the baiiles 22' progressively increase in height from front to rear. In locomotives of the type presently in general use the grate and trough assembly provides a successive overlapping of the baiiies if they be mounted with their upper edges substantially flush with the upper trough edges as disclosed in Figs. 8

to 11, inclusive.

As shown in Figs. 8 to 10, anangularly disposed baiiie 56 is mounted on the lower side of eachmud ring, each baffle being in the form of a flat strip 58 rigidly secured, as by welding, to the bottom of mud ring l6 so as to extend in wardly. beneath the side' edges of the grates. Strip 58 is cut away, as at 60, to provide air openings, and yet tosupport'the reversely bent portion 62 which deflects a portion of the incoming air to the edges of the grate areas. This ty e of angle baflle 56 has been found particularly cooperative with baflles 22 since, because of bailles 22, air entering through opening l4 travels substantially laterally inwardly, and not longitudinally of baflies 56, and therefore baflles-56 provide uniform and direct-lateral distribution of the air.

Fig. 11 illustrates a modified arrangement for obtaining positivelateral'distribution of air. In.

tailed in Figs. 8 to 10 inclusive, except that, instead ofbailles '56, a plurality of strips 51 are welded to theinner edges of bafiles' 22 so as to direct air to the sides of the grates. It will be noted that baflles 57 are so spaced and angularly disposed as to direct air substantially proportional to the areas between the projections of their planes.

The invention described above is not limited to the specific showing, but is intended to embrace all equivalents within the scope of the following claims.

I claim:

1. In a locomotivehaving an ash pan and an air inlet on each side thereof elongated in the fore-and-aft direction of the locomotive, a similarly elongated open-top trough shrouding each of said inlets, a series of bafiles in, each of said troughs, said bafiles having their surfaces lying generally transverse to the fore-and-aft direction of said locomotive, whereby to prevent substantial fore-and-aft movement of air in said inlets and to deter the formation of eddy currents in said inlets. V

2. In a locomotive having afire box, an ash pan, and an air inleton each side of the rash pan elongated inthe fore-and-aft direction I of the locomotive; a similarly elongated openrtop trough shrouding each of said inlets, a series of substantially flat bafiles in each of said troughs, to said bailies having substantially their entire surfaces lying at right, angles to the fo're-and-aft direction of the fire box and being spaced from one another.

3. In locnnotive fire box enclosing a combust-ion 1......a'mber, the cross section of which varies in size from front to rear, said fire box having side walls with elongated air inlet openin s associated therewith extending in the foreand-aft direction of the locomotive for feeding,

\ improvement which comprises a series of bailles airto the combustion chamber, a longitudinal open-top trough on the exterior of eachside of said fire box, said troughs respectively shrouding the openings, the improvement which comprises a series of generally flat baifles having surfaces disposed across the upper portions of each of said troughs, said baflles being longitudinally spaced from one another and having portions extending into said'air inlet openings the surfaces of said baflies being disposed transversely to the fore-and-aft direction of the locomotive.

4. The combination claimed in claim 3, the relative spacing between the bailles being proportional to the relative cross section of those portions of the combustion chamber lying inwardly thereof.

5. In a locomotive fire box including a top' wall,

havingopenings extending longitudinally of the fore-and-aft. direction of the locomotive therein for admitting air to said combustion spaces through said ash pan and said grate, and an opentop trough shrouding each of said openings, the

disposed in each of said troughs, the battles being spaced from one another, the relative spacing between the baflles being substantially directly proportional to the relative volumes of those portions of said combustion spaces respectively lying immediately inward thereof in a direction transversely to the fore-and-aft direction of the locomotive.

8. In a locomotive fire box including side walls,

a grate, and an ash pan below the grate, there being a substantially continuous longitudinal opening extending in the fore-and-aft direction of the locomotive between each of the side edges of the ash pan and the lower side edges oflthe side walls for admitting air to the ash panjt he improvement which comprises a trough on each side of said ash pan for shrouding the openings, and-a series of bailies disposed in each trough, the baflies being spaced from one another and being disposed in vertical planes lying generally transverse to the fore-and-aft dimensions of the locomotive.

9. In a locomotive firebox having side walls,

a grate, and an ash pan below the grate, there being a, substantially continuous opening extending longitudinally of the fore-and-aft direction of the locomotive between each side of the ash pan and the lower edge of the adjacent side wall, the improvement which comprises an open-top trough on each side of said ash pan shrouding said openings, 8. series of baflles in each trough, said baffles being spaced from one an-- other along the lengths of said troughs and having surfaces in said troughs disposed substantially transverse to the fore-and-aft dimensions of box 'irom outer edges disposed between the top and bot- 7 a a the troughs. and air distribution means extendinglongitudinally-oi the fire box and having surfaces inclined upwardly and inwardly oi the fire said openings and having their lower tom of said air openings. I

10. In a locomotive fire box including a top wall, side walls, a grate disposed across the lower J portion of said fire box, an ash pan below the grate, an arch defining a primary combustion space between the lower suriacethereoi and said of the fire box to provide further primary combustion space to the rear of said arch, said side walls having openings associated therewith extending longitudinally of the iore-andeaft direction of the locomotive ,for admitting air to said space between the lower surface thereof and said grate, the arch being spaced from the rear wall of the fire box to provide a further primary combustion space to the rear of said arch, said ash pan and said sidewalls having longitudinally extending openings therebetween i'or admitting air to said'combustion spaces through said ash Q pan and said grate, the improvement which comgrate, the arch being spaced from the rear wall combustion spaces through said ash pan and said grate, the improvement which comprises a trough on each side of said ash pan and lying outwardly of said openings, a plurality of upstanding baffles in each of said troughs, said bailles bein spaced from one another and having surfaces substantially normal to the fore andeaft dimensions ofthe openings and air distribution means extending longitudinally of the fire box and have prises an L-shaped trough on each side of saidl ash panv and extending outwardly of said openings, respectively, each of said troughs having a series of upstanding baflles, said baflles being spaced trom one another along the length oisaid forming each series respectively extending higher than the baflle in front thereof, save the first lastfie, whereby to expose a surface to rearwardly passing wind substantially unobstructed by the preceding baflie.

13. The combination claimed in claim 10, said air distribution means comprising a plurality of ing surfaces inclined upwardly and inwardly of y the-fire box from said openings and having their lower edges disposed between the top and bottom of said air openings so as to direct one portion oi the incoming air stream immediately upward Y and another portion of said air stream inwardlytowards the center of the ash pan.

11. The combination claimed in claim 10, the relative spacing between the bafiles being substantially directly proportional to the relative volume of those portions of said primary combustion spaces lying transversely inwardly of said spaces,

12.1.11 a locomotive fire boxincluding a top grate, and an arch defining'a primary combustion wall, side walls, a grate disposed across the lower 40 portion of said fire box, an ashpan beneath saiddefiector strips supported on the inner ends of VAUGHN MANSFV'IELD.

I REFERENCES CITED The following references are of record inthe file of this patent:

360,095 British Aug. 23, 1930 trough and respectively extending substantially thereacross, the "top edges of each or the baffles 

